On land they are lumbering, slow moving beasts. They lurk along the shallow waters everywhere from Africa to the coast lines of the Southeastern US, disguised by nature to grab unsuspecting passersby, be they fowl or fish, but recent studies show there is a lot more to these massive reptiles than meets the eye.
In fact, according to a paper published by zoologist Vladimir Dinets in 2013, both Mugger Crocodiles (Crocodylus palustris), a native of India, and the American Alligator (Alligator Mississippiensis) have been observed using twigs and sticks to lure in birds during their nesting seasons. Plenty of other animals, including everything from birds to primates, have used lures and tools to catch prey, so what is it that makes Dinets’ find so incredible?
This is the first known case of a predator not just using objects as lures, but taking into account the seasonality of prey behavior. It provides a surprising insight into previously unrecognized complexity of archosaurian ( lineage including Crocodiles, Dinosaurs, pterosaurs, et all) behavior. — Vladimir Dinets
Just how are the crocodiles using these sticks? Well, during the ‘building season’, water fowl, like cranes and egrets, are busy collecting twigs and sticks to build their large waterside nests. While normally vigilant about lurking water predators, the natural need to nest distracts the birds and gives the crocodiles the advantage they need. By carefully balancing sticks on the edge of the snout, the crocodiles and alligators need only be patient, and the prey will come to them.
“The crocodiles remain perfectly still for hours, and if they did move to change position, they did so in a way that the sticks remained balanced on their snouts, ” Dinets explains.
Are the crocodiles really watching the calendar to plan their hunt, or is this behavior a result of just too many twigs in the water? According to Dinets, who observed alligators at two separate egret nesting sites over two seasons, the behavior was predominately present during the breeding season and the alligators may even have to go out of their way to find the sticks as most available material is quickly rounded up by the birds. In a region where the local trees rarely shed branches, sticks are at a premium and the alligators use that as yet another advantage. After possibly hours of waiting, a busy nest building bird coming to retrieve what looks like free floating sticks is easy picking.
Dinets writes that it is possible the predators are reacting to the sudden presence of many water fowl, or that there may be other environmental clues that tip them off to their own version of hunting season, more research must be done to accurately determine just how these reptiles know when it’s time to break out the fishing sticks.
Crocodiles and alligators have long been viewed as dumb brutes, but this new research, alongside other evidence of more intelligent behavior such as advanced parental care and ”highly coordinated group hunting tactics,” continue to shed new light on the creatures, who have been around since well before man walked the Earth.
“These discoveries are interesting not just because they show how easy it is to underestimate the intelligence of even relatively familiar animals, but also because crocodiles are a sister taxon of dinosaurs and flying reptiles,” he concludes.
With many species of both alligator and crocodile listed as threatened or endangered due to over exploited hide hunting, new evidence that they are, indeed, intelligent and worth saving may well assist conservation efforts like those used to help the American Alligator move from the endangered to threatened species list. Not so lucky is its cousin, the American Crocodile, which is still an endangered species.
A terrifying creature of myth and legend, Dinets’ work shines a light on the real brains behind the brawn of these creatures, and with much of this research only at its beginning, we can be sure there is still a lot for us to learn.